Free screening Saturday at 6 p.m. at the Solidarity Center, 55 W. 17th St. To RSVP, call (212) 696-8562. For more info, go to Link (via Murketing)

Black radio didn’t exist before 1949, when Jack Gibson signed on Atlanta’s WERD, the first black-owned station in the country. But over the next several decades, hosts like Eddie O’Jay, Frankie Crocker, Hal Jackson (r.) and the legendary WWRL lineup became powerful community voices, delivering both entertainment and information.

Some of that remains today, with hosts like Imhotep Gary Byrd or Bob Slade, James Mtume and the WRKS team. But longtime city broadcaster and activist Bob Law, who was a prime force behind “Disappearing Voices,” warns that black radio’s impact today has been severely diminished – and not, he says, by accident.

Black radio was a major community organizing tool from the civil rights movement up through the Million Man March, which was almost ignored by “mainstream” media until a million men showed up. “If there was a situation where we needed 5,000 people at a rally, we could go on black radio and people would respond,” says the Rev. Al Sharpton. “Now it’s harder.”

“Disappearing Voices” also covers the broader history of black radio, with vintage clips of hosts like O’Jay, Enoch Gregory and Bobby Jay.

“It would take 50 films to tell it all,” executive producer Nana Soul noted on WBAI yesterday. “But it’s a part of our history people need to know.”

The statistics are not encouraging, Law points out in the film. Of some 12,000 radio stations today, only about 168 are black-owned.

Meanwhile, by coincidence, FCC Chairman Kevin Martin said this week he favors the XM and Sirius satellite radio merger if they set aside 4% of their channels for blacks and women. The Congressional Black Caucus rejected this as “completely unacceptable.”